Impact of Asteroid Defence

Impact of Asteroid Defence: Is it worth it?

Asteroid impacts are very bad, if the asteroid is big enough or is going fast enough. We should be able to defend against one, if we happen to find that one is coming toward us.

But defence against possible asteroid strikes will be very expensive since the BIGGEST problem is finding when one is coming in to hit us. The effort to find “dangerous” asteroids will probably involve fielding many space telescopes (to chart as many asteroids as possible–both those in a “near Earth orbit” as well as those in orbits which “swoop in” from the outer reaches of the Solar System). (To say nothing about watching for the kind of object that is generally speculated as having smashed/gouged the Moon out of the early Earth: “Loose” planetoids [and “Brown Dwarfs”?] which do not belong to any stellar system.)

To my mind, the best place to put computerized asteroid-charting space-telescopes would be co-located in the orbit of Mars—far enough out to give PLENTY of warning time and available to management/supervision from a human-based establishment on one of Mars’ moons (Phobos or Demos), or even on Mars, itself. (( Having “cut my alien-fighting teeth” as a cyber-space-ranger based on Phobos… :smiley: )) Both the automated space-telescopes and the management base (on Mars? Europa?) will be expensive, to say the least.

The impact of the asteroid-charting effort on the economy will be large (due to gravitational interactions, they change orbits not-infrequently so that the effort will be a never-ending project). But should even a single sizable or “too speedy” asteroid hit Earth in a populated area, the consequences will be nearly-unthinkable!

The Question: Is the cost of defending against the not-large chance of the truly hideous consequences of an asteroid strike worth it?

Well, what are the odds it’ll happen? How many near-civilization-destroying impacts have there been?

There are people out there who still doubt the validity of space station research of any kind, who feel that except for satellite communications, the space industry is a total waste of money.

I figure we’ll be at nearly Star Trek level space travel before any concrete plans are set in motion to watch out for stuff like this. Chances are pretty good we won’t get wiped out by an asteroid in the meantime.

Did you know that we are already looking for potentially hazardous objects in space? We’ve identified more than 300. So far, we’ve managed it without a Martian moonbase.

Haven’t you noticed that all the new comets are named "Linear… " these days ? Here’s the reason for it.

Knowing when the big one will hit is only the beginning of a solution. And it is the least troublesome part, as well. The other part is the system for changing the orbit, or destroying the suspected impact object.

That takes a system designed to apply large amounts of energy over astronomic distances, and it has to be ready and available for use under relatively short notice, in space. There are not too many design parameters for that that won’t also nicely fulfill the parameters for world dominating weapons platform. So who do we put in charge of the planet busting gun? Which threat seems to be likely to have a greater frequency of occurrence, the impact of a global effect asteroid, or the willful use of technology to destroy large numbers of people? I think I will ignore Chicken Little, one more time.


“The people have always some champion whom they set over them and nurse into greatness…This and no other is the root from which a tyrant springs; when he first appears he is a protector.” ~ Plato ~

Squink posted

Not exactly “all the new comets”. Here’s a news story link and a link to the “horse’s mouth”, about an amatuer astronomer who discovered a new comet ** just 5 days ago!** :slight_smile:

All of which also means that “Surprise!” is still a possibility, albeit much less likely than 10 years ago.

The most prolific comet-finder in the history of astronomy is the SOHO unmanned spacecraft, which has discovered 365 comets since it was put into service about five years ago. Most recently, it detected a comet just before it hit the Sun.

You are aware, of course, that Mars does not move in tandem with earth. The small arc of space that it could monitor is normally woefully out of synch with earth. This idea of yours… is not so good.

I think the first thing we need to do is buy all new globes. [sub]Apologies to King Ralph[/sub]

Well, I think I should be in charge of it!

But seriously, a far more efficient and economical way of dealing with problem asteroids (assuming the technology could be developed) would be to drop an automated mass-driver factory on it. It would be a lot easier to simply shift an asteroid’s orbit to a safe one than to destroy it.

You send a high-g rocket with robot assemblers to the asteroid. They begin mining the asteroid for materials to construct a mass driver. Then they use chunks of the asteroid itself as reaction mass to shift the orbit into a safe one. Maybe even drop it into a stable earth orbit so we could mine it.

Of course, we’d have to detect it far enough out to have time…

Yeah, I read too much science fiction.

yeah the mass thingie he just said and moving to mars to put all your eggs into more than one basket for safety ,

Ethilrist wrote:

Well, the Tunguska event happened less than a century ago. If it had hit a populated area, it would have erased said area from the map pretty effectively.

back to being is it worth it? , depends

if somebody puts up an anti asteroid missile defense network its obviously going to be abused as always see film
meteor or something “we’ve got enough missiles the’re just pointing the wrong way”

depends = how much you value your life , since if you are 2000 miles from a massive hit you are dead before you can even duck the blast , if you are outside then it would be midwinter for a longtime which would be a protacted survival of who has guns existance

however (me being the melanchany type) wouldn’t care too much if a big rock wiped me out since while a big rock isn’t wiping me out of existance i live a mundane existance
doing the same crud each day

Further, even if Mars did move in tandem with Earth, there is still the possibility that a comet/asteroid/loose planetoid/Richard Simmon’s ass/etc. could come from any of, oh, five other directions to strike Earth.

Best bet is to keep all satellites close to Earth, if such protocols are ever implemented.

Give the guy a break. He said ‘in the orbit of Mars’, not ON mars. Sheesh.

In truth, squeegee. In fact, on another Message Board which I’d rather not name since I’ve been BANNED there, the “working group” of which I’m a member proposed (a minimum of) 50 robotic asteroid-hunters/charters scattered around the Martian orbit; as well as a few in an orbit orthogonal to the eq. plane to chart those few, as SPOOFE indicated, which might come in from an unusual direction. As well as at least one in each of the (5?) stable spots (LaGrange??) in Earth’s orbit.

All VERY expensive. Including, of course, the semi-permanent base on Mars (Phobos? Deimos??) to maintain and supervise the network of asteroid-hunters/charters. (There is a serious problem of changing-trajectories due to gravitational interactions [et alles] which will necessitate a continual RE-plotting of asteroidal orbits; most especially NEO’s, which are, presumably, the most dangerous ones.) VERY EXPENSIVE!!

“What worth,” one must ask one’s budget director, “is the loss of a major city or of a large chunk of farm land due to the impact of an asteroid or comet?” Perhaps it would be better to just “kiss off” the potential loss of Denver or New York or DFW (—or, should it land in, say, the North Atlantic, most-all of the Eastern SeaBoard cities of the U.S.). Certainly it would conserve LARGE fiscal resources in these times of great need. :slight_smile:

Too expensive? ** That **is the question.

This site lists the following probabilities:
[ul][li]A collision capable of causing localized destruction. Such events occur somewhere on Earth between once per 50 years and once per 1000 years.[/li]
[li] A collision capable of causing regional devastation. Such events occur between once per 1000 years and once per 100,000 years.[/li]
[li] A collision capable of causing a global climatic catastrophe. Such events occur once per 100,000 years, or less often.[/ul][/li]How often has it happened? Lots of times.

I can agree with this part.

Fact of the matter is, we have PLENTY of resources here on earth to spot what needs to be spotted. I would not argue against the idea that we need to work a little faster on this task.

You seem to be missing a few fundemental concepts:

  1. We are capable of spotting anything dangerous from right here.
  2. All we have to do with astroids, is find them and accurately measure their orbits.
  3. If we accurately know the orbits we can forecast their positions for decades if not centuries.
  4. If we know all the fairly large object’s courses for decades in advance, it makes defending against one much easier.

The cost of doing the job properly is trivial. Probably less than a billion dollars. This would just be the cost of locating and getting accurate info on the orbits of all the NEO objects, not figuring out how to stop one from hitting.

But, the earlier an object is known to be dangerous, the easier/cheaper it will be to deal with it. If the object is still years away, it does not have to be moved in its orbit much to negate the threat.

I concur with scotth: we can find most of the important (read dangerous) objects using ground based observation. Unfortunately, we’re not doing even half the job we could; current estimates are that less than 7% of the possible NEOs have been identified.

Would be it be cost-effective (whatever that means – how do you measure the “cost” of, say, the deaths of a million or more people, or the destruction of a city?) to stop a collision with an NEO? It’s really not possible to say at this point – nobody really knows how to do it.

Triskadecamus, you don’t need a ‘planet busting gun’ to avoid a collision with an NEO, nor would such a thing be effective in any case. Forget what you saw in Deep Impact or Armageddon: if you blast a large object into a bunch of fragments, you haven’t altered it’s trajectory – you now have a zillion tons of fragments heading for you rather than one object, which is nearly as deadly.

As Ferrous correctly points out, what’s needed is to safely change an object’s orbit so that it is no longer on a collision course with us. How tough that would be would depend on the mass of the object and how far out it is from Earth when you try to change it’s course.

Did you miss this?:

Sheesh indeed.